Need some spindle help with school project

[bdog]

Whoops, this turned into quite the read....sorry folks.


I'm in my senior year studying mechanical engineering and am designing and building a commuter car. I have been heading up most of the design and analysis of the front suspension and I designed the front spindle similar to what you might find on a dune buggy. I'm now having a conflict with the machinist who's been talking to my instructor about my design and suggesting it's unsafe. I need help in finding examples of the design that I've already chosen which will help my case in a meeting I'm going to have today with both of them. The machinist is a race car enthusiast and knows quite a bit about suspension designs for race cars.

To my knowledge, there are 3 main spindle designs. Starting off, on solid axles which most of us want, there's the spindle which protrudes towards the outside of the vehicle and that is what the hubs rides on with bearings in between the 2 parts. I think this is the style that the machinist would like me to use.

Here's an exploded view:
http://www.pirate4x4.com/tech/billav...oded_small.jpg

Item 61 bolts onto item 50 making a complete and solid spindle. The hub then (item 66) rides on bearings which are slipped over the spindle (61)


Next up is something that you would find on most FWD cars and is very similar to the design that I'm trying to uphold but not exactly the same. The half shaft runs through the bearings which are pressed into the spindle and the hub mounts onto the part of the axle that protrudes from the spindle. Sorry, I couldn't find good pictures of this.


Finally, there's a spindle and a spindle spud making up the 2 main parts that I have spec'd for our commuter car.

Here's a cutaway drawing of what I have in mind.
http://i168.photobucket.com/albums/u171/yellowspeedracer/Untitled.jpg

The green part on the left is the spindle and the bearings are pressed into it. The red part is the spindle spud which I've already made myself. The hub, rotor and wheel all slip onto the spindle spud and rotate. In hindsight, I should've made the spindle myself, the machinist never would've had a say in the matter and none of this would be an issue but I didn't have time between going to school and working.

I spent most of last night googling anything I can think of to try to support my spindle/spindle spud suspension and haven't come up with much to present today. I know that most designs aren't like mine but that doesn't mean that those are the only ones that work. I've already invested $65 in bearings, $50 worth of 4130 and 6 hours into manufacturing the spindle spuds and a little less than a billion hours in analysis so changing the design at this stage would really blow. I'm hoping someone can provide me with examples of where my design is used in real life. Anything would work, I even tried to find information on tank spindle designs. I think 404s might use a similar design because I recall seeing pictures of 4mogger's spindle spuds on pirate with a hole drilled through them for CTIS but I couldn't find those pictures tonight. Pictures would be neat too.

Thanks in advance,

B

[05Willys]

I can't see either of your links

[Scott@Rockstomper]

Here's a cutaway drawing of what I have in mind.
http://i168.photobucket.com/albums/u...g?t=1207796492


You linkee no workee.

You're trying to turn the spindle around, put the bearings into the knuckle, slip the spindle through, put the wheelbearing nut on the inside, and bolt the wheel to the spindle flange?

If so, that's a Ford front 60 unit bearing, stop by (soon, before I make another scrap run) and I'll give you one out of my scrap bin.

If not, I can't follow your description without a picture.

Edit: Oh, and (a) WTF is your machinist doing talking to your instructor, (b) is your instructor planning on letting you "test" this thing on open roads, (c) never tell a non-captive machinist what they're making parts for, just give them prints and specs.

[svoman2300]

I'm now having a conflict with the machinist
B

My dad was tool and die maker/machinist for many years and I remember him coming home from work many times bitching about the "punk" (his words) engineers and having to help them rework thier designs. Good luck with your project.

[bdog]

One of the links is fixed. I'll work on the other in a second.

You're trying to turn the spindle around, put the bearings into the knuckle, slip the spindle through, put the wheelbearing nut on the inside, and bolt the wheel to the spindle flange?

Indeed, that sounds about right.

If so, that's a Ford front 60 unit bearing, stop by (soon, before I make another scrap run) and I'll give you one out of my scrap bin.

That's nice of you but I don't think I need one, I'll look for pictures though. Do you mean a 1960's Ford or a Dana 60?



Edit: Oh, and (a) WTF is your machinist doing talking to your instructor, (b) is your instructor planning on letting you "test" this thing on open roads, (c) never tell a non-captive machinist what they're making parts for, just give them prints and specs.

a - he has done it behind without me knowing, so we'll see what happens today. b - open roads, I would doubt it but we will for sure drive it in the parking lots on campus. c - I hadn't planned on it but he's been bugging my group for assembly drawings so I broke down and gave them to him.



My dad was tool and die maker/machinist for many years and I remember him coming home from work many times bitching about the "punk" (his words) engineers and having to help them rework thier designs. Good luck with your project.

I completely understand where your dad was coming from. I have a year experience working on a mill and a lathe so I have a good idea of what can be made easily, what's hard to make and what can't be made at all. I helped with some redesign and made suggestions on other parts of car that have made manufacturing easier. None of that pertains to the issues I'm having now.


Thanks for the input guys!

[Scott@Rockstomper]

That's nice of you but I don't think I need one, I'll look for pictures though. Do you mean a 1960's Ford or a Dana 60?

Late (current) model Ford Dana 60. Front end specifically. Same unit bearings that Spidertrax uses on their Spider9 knuckles.

Looking at the pic that you have, that's what you've basically got. The Ford 60 unit bearing actually is a removable bearing housing that indexes into, and bolts onto, a knuckle, rather than having the bearing journal directly in, a knuckle.

A similar design concept is also used on VW rearends--not the new VW, the old Beetle. 60's and 70's vintage aircooled rearengine Beetles.

I disapprove of the air gap between the hub and the rotor--under side loading, your design will break the wheel and/or rotor unless you make the spindle spud flange big enough to accomodate the wheel pattern with enough excess to support the entire backside of the wheel flange. Or cut a recess into the hub or rotor to accomodate the small flange, such that the hub and rotor fit up to one another without air gap.

c - I hadn't planned on it but he's been bugging my group for assembly drawings so I broke down and gave them to him.

"Sorry, those're proprietary drawings that we can't let leave the building."

I know, doesn't work for you very well (yet) since you're still a student, but you might want to practice it. Assembly drawings leaving the company is a fireable (or worse) offense at most companies where you'll be looking for a job in a couple years. ;)

[bdog]

Thanks a bunch Scott!

I had planned on cutting a recess into the hub so that it sits flush with the front of the flange....we're on the same page.

I should also clarify that the machinist works in the machine shop on campus. He's not exactly an outside machine shop that we're paying.

[bdog]

Catastrophe has been avoided. Thanks again for the help!